Paxlovid Dosing for a 50-Year-Old Male with Normal Renal Function
The recommended dose of Paxlovid for a 50-year-old male with normal renal function is 300 mg nirmatrelvir (two 150 mg tablets) with 100 mg ritonavir (one 100 mg tablet) taken together twice daily for 5 days.
Dosage Details
The standard Paxlovid regimen consists of:
- Nirmatrelvir: 300 mg (two 150 mg tablets)
- Ritonavir: 100 mg (one 100 mg tablet)
- Frequency: Twice daily
- Duration: 5 days
- Administration: With or without food, at approximately the same time each day
This dosing is based on the FDA-approved labeling for Paxlovid 1, which provides clear guidance for patients with normal renal function.
Renal Considerations
The standard dose of 300 mg nirmatrelvir with 100 mg ritonavir twice daily is appropriate for patients with:
- Normal renal function
- Mild renal impairment (eGFR ≥60 mL/min)
For patients with moderate renal impairment (eGFR 30-59 mL/min), the dose should be reduced to 150 mg nirmatrelvir with 100 mg ritonavir twice daily 1, 2.
For patients with severe renal impairment (eGFR <30 mL/min), Paxlovid use requires careful consideration and modified dosing 3.
Administration Guidelines
- Take all tablets together at the same time
- Swallow tablets whole - do not chew, break, or crush
- Take with or without food
- If a dose is missed within 8 hours of the scheduled time, take it as soon as possible and resume normal schedule
- If more than 8 hours have passed, skip the missed dose and take the next dose at the regular time
- Do not double the dose to make up for a missed dose 1
Important Drug Interaction Considerations
Ritonavir is a potent CYP3A4 inhibitor and can cause significant drug interactions. Before prescribing Paxlovid:
- Review all patient medications for potential interactions
- Consider temporarily pausing certain medications during the 5-day Paxlovid course if necessary
- Use drug interaction checking tools to identify potential interactions 4
Clinical Pearls
- Paxlovid must be initiated within 5 days of symptom onset for maximum efficacy 5
- The complete 5-day course should be taken even if symptoms improve
- Nirmatrelvir is primarily eliminated renally when co-administered with ritonavir 6
- Population pharmacokinetic studies support the 300 mg/100 mg twice daily dosing for patients with normal renal function 2
By following these dosing guidelines, you can optimize the efficacy of Paxlovid treatment while minimizing the risk of adverse effects in a 50-year-old male patient with normal renal function.